The building industry and, in particular, the housing industry, remains anachronistic in the extreme as it fails to take any real advantage of the technological sophistication now available. Until recently, the profession of architecture has opposed the use of mass production techniques for building, arguing that the standardization principle which is the modus operandi of industrial production inevitably leads to a standardized uniform environment. As a consequence of their position they have almost totally avoided the problems of mass housing. The result of this is that housing has been left entirely to the local builder who is limited by old fashioned techniques and an accomodation to the need for diversity that is at best marginal.
Per capita resources are diminishing as the population continues to grow at an astonishing rate. This alone is a clear enough mandate for an economical use of natural resources. Both the short and long range costs of building increase. The short range cost is a function of both economy of means and resource utilization. The high range cost is primarily a function of the building industry's failure to recognize in any practical way the need for change. The principle of environmental adaptability as an economic advantage has not been understood. Total building costs should be based not only on original construction but upon the costs of subsequent change.
The industrial production principle of standardization is really a principle of economy, economy of means as well as economy of resource utilization. Although there are innumerable examples of the misuse of technology, there is ample enough evidence to show that well designed mass production techniques can produce more with less resources and in less time that any other alternative strategy. The task clearly becomes one of reconciling the principles of industrial production technique, i.e. standardization with the human and ecological realities of change and diversity.
In order to take best advantage of mass production techniques what is needed are systems which use standardized components, yet a set of such components is needed which can be combined in different ways to yield a great variety of alternative structures. What in fact is required are systems composed of minimum sets of component types which are designed in such a way that they may be combined and recombined into an endless diversity of form.
Modular structures can be defined in terms of volumes, surfaces, or linear frameworks. The latter is the more fundamental in a geometric sense, as surfaces can be defined by linear frames, and volumes can be defined by surfaces (and frames). Any framework must consist of nodes (or vertices) and branches (or edges). A framework is simply the interconnections of points in space with linear branches. In a physical structural system the points or nodes become connectors, and the branches become linear structural components or struts.
In addition to a consideration of the purely spatial properties of modular systems (be they frames, surfaces, or volumes) it is also necessary to study carefully the physical consequences of alternative spatial arrangements. In so far as framework structures are concerned, triangulated configurations give rise to the most efficient systems from the point of view of strength per unit of invested resources, i.e. strength per weight. This has been known to aircraft frame designers for many years. It is a point that has been recently poplularized by R. Buckminster Fuller with his geodesic domes.
It can easily be shown that the triangle is the only inherently stable linear framework. All other polygons with more than three sides are unstable. If a triangular frame is constructed in which all of its joints are hinges, it remains just as rigid as if its joints were fixed. If a square or any other polygon is constructed with hingeable joints, it will immediately collapse. Complex structures that are fully triangulated can be constructed with multi-directional hinges at each joint, yet they will remain completely rigid.
There is a two-fold economic advantage in inherently stable triangulated structures: first, their tendency to disperse concentrated and distributed loads over a very large part of the structure and, second, the fact that loads are distributed axially through the linear members. Both of these are ideal conditions for efficient use of materials.
When linear members are loaded axially along their lengths, they experience no bending, only pure compression or pure tension. With complex triangulated frameworks, the direction of loads become far less important than in the usual rectangular based structural design.
Prior art techniques have relied primarily upon a vertical and horizontal structural member to create buildings. Where necessary, framing members which include diagonal braces are added to provide lateral rigidity to the inherently non-rigid orthogonal frameworks. Triangulated structures are therefore the exception and there, general use has been limited.
Triangulated systems have not been used extensively in architectural structures, possibly because they are largely incompatible with the architectural profession's spatial sensibilities which appear to be dominated by right angles. Looking at space from a more fundamental and comprehensive point of view, a modular spatial approach can be found which can yield inherently stable, highly efficient, low redundancy structures based upon fully triangulated configurations.
Although such structures are derived primarily from triangular matrices, rather than eliminate the familiar 90.degree. spatial possiblities, they have been augmented and redefined in such a way as to yield a vast array of new options for spatial planning.
One of the disadvantages of triangulated systems is the relatively complex nodes that are necessary for joining the many linear members that can frequently meet at a common point. This disadvantage can be overcome in the context of high volume industrial production. A sophisticated, specially designed joint system can then become economically feasible, which would not be the case if one were building a single structure or relatively small numbers of small-scale structures.
According to the present invention, a minimum inventory, maximum diversity building system includes a triangulated structural framing to which various interstitial panels are attached forming a space enclosing system, or a weather envelope. A basic framework is the precursor of the space enclosing panel system. In the preferred embodiment, the modular framework system consists of three primary and three secondary linear components which, in turn, combine in various ways to define a set of basic, interstitial panels.
The interrelatedness of the six linear components is shown in Table I below.
TABLE I ______________________________________ PRIMARY COMPONENTS A = Unity B = A.sqroot.6/4 = .6123A C = A.sqroot.3/3 = .5774A SECONDARY COMPONENTS D = A.sqroot.2/2 = .7072A E = A.sqroot.6/6 = .4082A F = A.sqroot.6/12 = .2041A ______________________________________
The relative edge length ratios are given as functions of unit edge A. The A, B, and C components are considered primary, and the D. E. and F components are considered secondary by virtue of the frequency of their use. Note that these ratios are node center to node center distances and not actual component lengths, since the bulk of the nodal joints would have to be allowed for.
A plurality of triangular, interstitial panels can be defined by the linear components. The sides and various face angles are given in Table II below.
TABLE II ______________________________________ PRIMARY PANELS Panel Sides Angles ______________________________________ 1 B.sup.. A.sup.. B 35.degree.16, 109.degree.28', 35.degree.16' 2 B.sup.. C.sup.. B 61.degree.51', 56.degree.16', 61.degree.52' SECONDARY PANELS 3 B.sup.. D.sup.. B 54.degree.44', 70.degree.32', 54.degree.44' 4 D.sup.. C.sup.. D 65.degree.54', 48.degree.12', 65.degree.54' 5 B.sup.. E.sup.. B 70.degree.32', 38.degree.56', 70.degree.32' 6 B.sup.. F.sup.. C 70.degree.32', 19.degree.28, 90.degree. TERTIARY PANELS 7 D.sup.. A.sup.. D 45.degree. 90.degree. 45.degree. 8 C.sup.. A.sup.. C 30.degree. 120.degree. 30.degree. 9 C.sup.. C.sup.. C 60.degree. 60.degree. 60.degree. ______________________________________
Like the linear components, these nine surfaces are ranked according to the frequency of their use. The linear members and these panels constitute components which relate to each other in periodic associations.
It is important to note that no particular scale has been assigned these components. The actual size of the members is determined by the spatial requirements of the given applications. The important thing in this concept is the relative metric and topological relations among the components. A few specific sizes emerge as the most appropriate accommodations of human scale.
Each panel can be produced as an opaque insulated surface, as a translucent surface for diffused lighting, or as a transparent window. In addition to these examples, it would also be possible to have panels of differing coefficients of reflectance of radiant energy. The linear framework structure is envisioned as a demountable system to facilitate both erection and change, and the panels are intended to be replaceable and changeable as well. This is possible because the integrity of the building structure is entirely in the frame. The panels are only required to resist local loads.
This simple collection of components can be assembled in great varieties of architectural configurations, including single story dome-like dwellings, and multilevel low and high rise structures. The system provides for the structural framework, the space enclosing and finishing surfaces, a partitioning system for interior space, and a flooring system including integral foundations. The application of such adaptable environmental systems will be found wherever high strength per weight, mass producible, economical, variable and diverse human environments are desirable.
The novel features which are believed to be characteristic of the invention, both as to organization and method of operation, together with further objects and advantages thereof will be better understood from the following description considered in connection with the accompanyng drawings in which several preferred embodiments of the invention are illustrated by way of example. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention.